Influence of Hibernation on Survival Time and Weight Loss of X-Irradiated Ground Squirrels.

Abstract

Comparison was made of the susceptibility of hibernating and non-hibernating ground squirrels (Citellus tridecemlineatus) to the lethal action of ionizing radiation. The 30-day LD50 of X-rays for non-hibernating ground squirrels was estimated to be approx. 700 r. Non-hibernating animals given 800 r of X-rays exhibited over 80% mortality within 10 days. Ground squirrels irradiated while in hibernation and maintained in the hibernating state following irradiation exhibited no mortality within 30 days. When these animals were returned to the homeo-thermic state either at 2 wks or 4 wks. after irradiation death ensued within 10 days. Animals that maintained in hibernation following lethal doses of X-rays eventually succumbed although survival was greatly prolonged. Thus, while hibernation markedly increased survival time in this sp. following lethal doses of X-rays, it did not alter ultimate mortality.